One of Britain's biggest supermarket chains is helping to bankroll the Queen's Diamond Jubilee celebrations.

Sainsbury's is the first corporate sponsor to pick up the tab for a major event marking the monarch's 60-year reign, the Standard can reveal.

It is to host a three-day open-air festival in Hyde Park, starting on June 2, and is also in talks to help fund the £10million Thames river pageant that will form the showpiece of the celebrations.

The firm is one of several major donors believed to be in talks to underwrite the river pageant, whose organisers are counting on a £2million VAT rebate from Chancellor George Osborne.

The Government has provided £1million to the Queen to cover her travel and official engagements in the Jubilee year but other events have to rely on fund-raising or corporate donations.

Sainsbury's will attempt to recoup the cost of its three-day "Pageant in the Park" by setting up "brand activation areas" where dozens of "partner" firms can promote their goods to crowds of up to 50,000 a day.

It has asked Westminster council for permission to erect two stages and a "variety tent".

There will be marching bands, orchestral recitals, West End musicals and Commonwealth dancers in a programme designed to showcase "Britain through the decades".

On show will be "roaming" enter- tainers, such as stilt-walkers and face-painters, while part of the parade ground will host military displays.

Crowds will be able to watch pictures of the June 3 river pageant on four giant TV screens.

The festival will not be open for the pop concert being staged outside Buckingham Palace on June 4 but on June 5 will coincide with a royal procession to St Paul's Cathedral.

The event plan promises to focus on "family entertainment", adding: "The performances will highlight the best of British performances and will include dance, theatre, classical and popular musical entertainment.

"There will be no 'rock bands' or performances that would be unsuitable for a family audience."

A Sainsbury's spokeswoman said: "We are looking at a number of ways to celebrate the exciting events taking place this summer, such as the Queen's Diamond Jubilee and the Olympic and Paralympic Games.

"We are still at the early planning stages on some of this activity and will be sharing our plans over the coming months."

Westminster council has also received an application from the BBC for the concert on the evening of June 4.

This would see seating erected around the Queen Victoria memorial for 12,000 people, with a further 10,000 standing.

The line-up, which is now being co-ordinated by Take That frontman Gary Barlow, is due to be unveiled next month. One possible plan is to allow singers to perform from the balcony of the palace.